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1999

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Articles 361 - 390 of 2555

Full-Text Articles in Physical Sciences and Mathematics

When The Necessary Conditions Are Not Sufficient: Sequences With Zero Autocorrelation Function, J. Horton, Jennifer Seberry Sep 1999

When The Necessary Conditions Are Not Sufficient: Sequences With Zero Autocorrelation Function, J. Horton, Jennifer Seberry

Faculty of Informatics - Papers (Archive)

Recently K. T. Arasu (personal communication) and Yoseph Strassler, in his PhD thesis, The Classification of Circulant Weighing Matrices of Weight 9, Bar-Ilan University, Ramat-Gan, 1997, have intensively studied circulant weighing matrices, or single sequences, with weight 9. They show many cases are non-existent. Here we give details of a search for two sequences with zero periodic autocorrelation and types (1,9), (1,16) and (4,9). We find some new cases but also many cases where the known necessary conditions are not sufficient. We instance a number of occasions when the known necessary conditions are not sufficient for the existence of weighing …

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Notes On Learning Probabilistic Automata, Alberto Apostolico Sep 1999

Notes On Learning Probabilistic Automata, Alberto Apostolico

Department of Computer Science Technical Reports

No abstract provided.

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A Multi-Plane State Machine Agent Model, Ladislau Bölöni, Dan C. Marinescu Sep 1999

A Multi-Plane State Machine Agent Model, Ladislau Bölöni, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.

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An Algorithm For Parallel 3d Reconstruction Of Asymmetric Objects From Electron Micrographs, Robert E. Lynch, Hong Lin, Dan C. Marinescu Sep 1999

An Algorithm For Parallel 3d Reconstruction Of Asymmetric Objects From Electron Micrographs, Robert E. Lynch, Hong Lin, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.

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Moolapheonoides Utmas, New Species, From Coral Reefs In The Madang Lagoon, Papua New Guinea (Amphipoda, Cyproideidae), James Darwin Thomas Sep 1999

Moolapheonoides Utmas, New Species, From Coral Reefs In The Madang Lagoon, Papua New Guinea (Amphipoda, Cyproideidae), James Darwin Thomas

Marine & Environmental Sciences Faculty Articles

Moolapheonoides utmas, new species, is described from coral reefs at Madang, Papua New Guinea. M. utmas differs from other species in the genus by the large tooth-cusp projecting posteroventrally on article 2 of pereopod 7 and the lower dorsal crest of the urosome. It shares an unusual dorsolateral bulbous projection of pereonite segments 3 and 4 with other cyproideid species Hoplopohoenoides obessa Shoemaker from Florida, and Naraphoenoides mullaya Barnard from Australia. Identification keys for the genus Moolaphoenoides are presented and relationships to other genera in the family are discussed.

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Aerodynamic Damping Predictions For Turbomachine Blade Rows Using A Three- Dimensional Time Marching Simulatiions, Dana A. Gottfried, Sanford Fleeter Sep 1999

Aerodynamic Damping Predictions For Turbomachine Blade Rows Using A Three- Dimensional Time Marching Simulatiions, Dana A. Gottfried, Sanford Fleeter

Department of Computer Science Technical Reports

No abstract provided.

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Fatigue Life Prediction Of Turbomachine Blading, Sanford Fleeter, Chem Zhou, Elias N. Houstis, John R. Rice Sep 1999

Fatigue Life Prediction Of Turbomachine Blading, Sanford Fleeter, Chem Zhou, Elias N. Houstis, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

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Table Of Contents Volume 10, Number Four, Fall 1999, Risk Editorial Board Sep 1999

Table Of Contents Volume 10, Number Four, Fall 1999, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Table of contents for the journal RISK: Health, Safety & Environment (ISSN: 1073-8673)

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Quasicoherent Nucleation Mode In Two-Phase Nanomagnets, Ralph Skomski, J. Ping Liu, David J. Sellmyer Sep 1999

Quasicoherent Nucleation Mode In Two-Phase Nanomagnets, Ralph Skomski, J. Ping Liu, David J. Sellmyer

David Sellmyer Publications

Magnetization processes in advanced magnetic nanostructures are investigated. For the case of spherical soft or semihard grains surrounded by a very hard matrix a bulging nucleation mode is discovered. The bulging mode exhibits the radial angular symmetry of the coherent mode, but it is incoherent due to its radial variation. The radial dependence of the bulging mode is obtained by solving a spherical Bessel equation which is subject to appropriate boundary conditions. In contrast to the coherent mode, the bulging mode yields a nucleationfield coercivity which depends on the exchange stiffness and on the size of the grain. There is …

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Design Approaches To Model-Based Simulation In Intelligent Computer Assisted Instruction, Bjoern Helfesrieder, Venky Shankararaman Sep 1999

Design Approaches To Model-Based Simulation In Intelligent Computer Assisted Instruction, Bjoern Helfesrieder, Venky Shankararaman

Research Collection School Of Computing and Information Systems

Model-based simulation systems have been created in various fields of engineering to train personnel or students in operation, maintenance and troubleshooting of complex devices and systems. A review of literature indicates a lack of good overviews of the approaches to system design of model-based training simulations in Intelligent Computer Assisted Instruction (ICAI). Though single systems have to some extent been evaluated with regard to their performance, an organised evaluation, especially a comparative evaluation of the systems that have been created within the field is lacking. To be able to successfully conduct an in-depth review under these conditions, we concentrate and …

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Stability Of Self-Similar Solutions For Van Der Waals Driven Thin Film Rupture, Thomas P. Witelski, Andrew J. Bernoff Sep 1999

Stability Of Self-Similar Solutions For Van Der Waals Driven Thin Film Rupture, Thomas P. Witelski, Andrew J. Bernoff

All HMC Faculty Publications and Research

Recent studies of pinch-off of filaments and rupture in thin films have found infinite sets of first-type similarity solutions. Of these, the dynamically stable similarity solutions produce observable rupture behavior as localized, finite-time singularities in the models of the flow. In this letter we describe a systematic technique for calculating such solutions and determining their linear stability. For the problem of axisymmetric van der Waals driven rupture (recently studied by Zhang and Lister), we identify the unique stable similarity solution for point rupture of a thin film and an alternative mode of singularity formation corresponding to annular “ring rupture.”

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The Probe, Issue 204 - September 1999 Sep 1999

The Probe, Issue 204 - September 1999

The Probe: Newsletter of the National Animal Damage Control Association

USFWS to Explore Canada Goose Management Strategies -- from a press release issued Aug. 3 by the US. Fish & Wildlife Service, written by Chris Tollefson.
Anti-Trapping Measure Passes House
Oregon Legislature Moves To Ensure Safety Of Its Citizens Against Cougars
Acord Promoted Away From Wildlife Services
New State Director US DA/APHIS in Mississippi is Kristina Godwin
BOOk R e v i e w : "Living With Wildlife: How to Enjoy, Cope With, and Protect North America's Wild Creatures Around Your Home and Theirs," The California Center for Wildlife, with Diana Landau and Shelley Stump. San Francisco: A Sierra Club …

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Examination Of Ionic Liquids And Their Interaction With Molecules, When Used As Stationary Phases In Gas Chromatography, Daniel W. Armstrong, Lingfeng He, Yan Song Liu Sep 1999

Examination Of Ionic Liquids And Their Interaction With Molecules, When Used As Stationary Phases In Gas Chromatography, Daniel W. Armstrong, Lingfeng He, Yan Song Liu

Chemistry Faculty Research & Creative Works

Stable room-temperature ionic liquids (RTILs) have been used as novel reaction solvents. They can solubilize complex polar molecules such as cyclodextrins and glycopeptides. Their wetting ability and viscosity allow them to be coated onto fused silica capillaries. Thus, 1-butyl-3- methylimidazolium hexafluorophosphate and the analogous chloride salt can be used as stationary phases for gas chromatography (GC). Using inverse GC, one can examine the nature of these ionic liquids via their interactions with a variety of compounds. The Rohrschneider-McReynolds constants were determined for both ionic liquids and a popular commercial polysiloxane stationary phase. Ionic liquid stationary phases seem to have a …

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Comparison Of Magnetic Images Using Point And Thin-Film Magnetic Force Microscopy Tips, Sy_Hwang Liou Sep 1999

Comparison Of Magnetic Images Using Point And Thin-Film Magnetic Force Microscopy Tips, Sy_Hwang Liou

Sy-Hwang Liou Publications

The magnetic images of a magnetic reference sample were compared using point and thin-film magnetic force microscopy (MFM) tips. The thin film MFM tip was made by magnetron sputtering of an amorphous metal. The point MFM tip was made by an ion milling process that produces a small magnetic particle on the cantilever. Our results clearly demonstrated that the volume of magnetic material involved in the tip-sample interaction is much reduced in the case of the point tip compared to that of the thin film tips. By comparing the magnetic images of a tri-bit pattern on a magnetic reference sample, …

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Parity Violation In Neutron Resonances Of 103rh, D A. Smith, J D. Bowman, Bret E. Crawford, C A. Grossmann, T Haseyama, A Masaike, Y Matsuda, G E. Mitchell, S I. Penttila, N R. Roberson, S J. Seestrom, E I. Sharapov, Sharon L. Stephenson, V W. Yuan Sep 1999

Parity Violation In Neutron Resonances Of 103rh, D A. Smith, J D. Bowman, Bret E. Crawford, C A. Grossmann, T Haseyama, A Masaike, Y Matsuda, G E. Mitchell, S I. Penttila, N R. Roberson, S J. Seestrom, E I. Sharapov, Sharon L. Stephenson, V W. Yuan

Physics and Astronomy Faculty Publications

Parity nonconservation (PNC) was studied in p-wave neutron resonances of 103Rh in the neutron energy range 30 to 490 eV. The helicity dependence of the neutron total cross section of rhodium was determined by capture measurements with the time-of-flight method at the Manuel Lujan Neutron Scattering Center at the Los Alamos National Laboratory. A total of 32 p-wave resonances were studied and statistically significant longitudinal asymmetries were observed for resonances at En=44.5, 110.8, 321.6, and 432.9 eV. A statistical analysis treating the PNC matrix elements as random variables yields a weak spreading widthΓw=(1.42-0.59+1.21 …

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Addendum: "Bethe Stopping-Power Theory For Heavy-Target Atoms", P.T. Leung Sep 1999

Addendum: "Bethe Stopping-Power Theory For Heavy-Target Atoms", P.T. Leung

Physics Faculty Publications and Presentations

Our previous result on the correction of the Bethe stopping power theory for heavy target elements is amended, with the application of a more consistent version of the semirelativistic Bethe sum rule worked out recently [Phys. Rev. A 57, 4994 (1998)]. This correction is found to be significant for high-Z target atoms and relatively high-energy incident particles.

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Illinois River 1998 Nutrient And Suspended Sediment Loads At Arkansas Highway 59 Bridge, Marc A. Nelson, Thomas S. Soerens Sep 1999

Illinois River 1998 Nutrient And Suspended Sediment Loads At Arkansas Highway 59 Bridge, Marc A. Nelson, Thomas S. Soerens

Technical Reports

Automatic water samplers and a U.S. Geological Survey (USGS) gauging station were established in 1995 on the main stem of the Illinois River at the Arkansas Highway 59 Bridge. Since that time, continuous stage and discharge measurements and water quality sampling have been used to determine pollutant concentrations and loads in the Arkansas portion of the Illinois River. This report represents the results from the measurement and sampling for January 1, 1998 to December 31, 1998.

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Optoelectronic Switching Network With 2d Optical Fiber Bundle Array I/O Access Device, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Yuan-Zhong Xu Sep 1999

Optoelectronic Switching Network With 2d Optical Fiber Bundle Array I/O Access Device, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Yuan-Zhong Xu

Electro-Optics and Photonics Faculty Publications

An optoelectronic switching network with 2-D optical fiber bundle arrays I/O access device is presented in this paper. An optoelectronic recirculating Banyan network based on CMOS/SEED smart pixel device is used in this configuration. Thirty-two X two single-mode fiber bundle array and 32 X 2 multi- mode fiber bundle array are fabricated respectively based on the features of high density, high precision and array permutation of the CMOS/SEED optoelectronic integrated devices. The measuring results show that the center to center spacing between adjacent optical fibers in the same layer of the fiber array is 125 micrometer, and the spacing between …

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Effects Of The Vertical Plasma Drift Velocity On The Generation And Evolution Of Equatorial Spread F, Bela G. Fejer, L. Scherliess, E. R. De Paula Sep 1999

Effects Of The Vertical Plasma Drift Velocity On The Generation And Evolution Of Equatorial Spread F, Bela G. Fejer, L. Scherliess, E. R. De Paula

Bela G. Fejer

We use radar observations from the Jicamarca Observatory from 1968 to 1992 to study the effects of the F region vertical plasma drift velocity on the generation and evolution of equatorial spread F. The dependence of these irregularities on season, solar cycle, and magnetic activity can be explained as resulting from the corresponding effects on the evening and nighttime vertical drifts. In the early night sector, the bottomside of the F layer is almost always unstable. The evolution of the unstable layer is controlled by the history of the vertical drift velocity. When the drift velocities are large enough, the …

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Summary Of Historical Information Relevant To The Hydrobiological Monitoring Of The Lower Peace River And Upper Charlotte Harbor Estuarine System, Pbs&J, Inc. Sep 1999

Summary Of Historical Information Relevant To The Hydrobiological Monitoring Of The Lower Peace River And Upper Charlotte Harbor Estuarine System, Pbs&J, Inc.

Reports

This review is focused on the relationship between plankton communities in Upper Charlotte Harbor and changes in freshwater flows that might result from Peace River water withdrawals. There are lour mechanisms by which freshwater withdrawals from the Peace River could influence plankton communities within the Lower Peace River and Upper Charlotte Harbor estuarine system. The first mechanism would involve removing enough water to cause the geographical location of mean isohalines to shift. If the locations shifted enough that isohalines lie over areas with different physical or biological habitats than the areas currently occupied, a significant biological effect might result. The …

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Final Intrinsic Remediation, Engineering Evaluation/Cost Analysis Addendum For Ust Site 870, Hill Air Force Base, Ogden, Utah, Parsons Engineering Science, Inc. Sep 1999

Final Intrinsic Remediation, Engineering Evaluation/Cost Analysis Addendum For Ust Site 870, Hill Air Force Base, Ogden, Utah, Parsons Engineering Science, Inc.

All U.S. Government Documents (Utah Regional Depository)

This report was prepared for the Air Force Center for Environmental Excellence (AFCEE) by Parsons Engineering Science, Inc. (parsons ES) as an update to the Final Intrinsic Remediation Engineering Evaluation/Cost Analysis (EE/CA) for Underground Storage Tank (UST) Site 870, Hill Air Force Base (AFB), Utah (parsons ES, 1995). The EE/CA was conducted to evaluate the use of intrinsic remediation with long-term monitoring (LTM) for remediation of fuel hydrocarbon contamination dissolved in groundwater at UST Site 870. This update summarizes the results of the third sampling event performed as part of longterm groundwater monitoring at the site. This sampling was conducted …

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Mössbauer Effect Study Of Filled Antimonide Skutterudites, Gary J. Long, Dimitri Hautot, Fernande Grandjean, Donald T. Morelli, Gregory P. Meisner Sep 1999

Mössbauer Effect Study Of Filled Antimonide Skutterudites, Gary J. Long, Dimitri Hautot, Fernande Grandjean, Donald T. Morelli, Gregory P. Meisner

Chemistry Faculty Research & Creative Works

The iron-57 Mössbauer spectra of a series of Ce-filled antimonide skutterudites, CexFe4-yCoySb12, where x varies from 0.22 to 0.98 and y varies from 0 to 3.5, have been measured at 295 K. In addition, the spectra of Ce0.60Fe2Co2Sb12 and Ce0.82Fe3CoSb12 have been measured from 85 to 295 K and the spectra of Ce0.35FeCo3Sb12 and Ce0.98Fe4Sb12 have been measured from 4.2 to 295 K. The spectra, all of which consist of …

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Contour Temperature Programmed Desorption For Monitoring Multiple Chemical Reaction Products, Charles C. Chusuei, J. V. De La Peña, John A. Schreifels Sep 1999

Contour Temperature Programmed Desorption For Monitoring Multiple Chemical Reaction Products, Charles C. Chusuei, J. V. De La Peña, John A. Schreifels

Chemistry Faculty Research & Creative Works

A simple method for obtaining a comprehensive overview of major compounds desorbing from the surface during temperature programmed desorption (TPD) experiments is outlined. Standard commercially available equipment is used to perform the experiment. The method is particularly valuable when high molecular mass compounds are being studied. The acquisition of contour temperature programmed desorption (CTPD) spectra, sampling 50-dalton mass ranges at a time in the thermal desorption experiments, is described and demonstrated for the interaction of benzotriazole adsorbed on a Ni(111) surface. Conventional two-dimensional TPD spectra can be extracted from the CTPD by taking vertical slices of the contour.

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Measurement Of The BD0B̅D0 Oscillation Frequency Using Dimuon Data In Pp̅ Collisions At √S =1.8tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Sep 1999

Measurement Of The BD0B̅D0 Oscillation Frequency Using Dimuon Data In Pp̅ Collisions At √S =1.8tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a measurement of the mass difference Δmd of the two Bd0 mass eigenstates. We use a flavor tagging method based on the lepton charge, in a sample of events with two muons at low transverse momentum. The sample corresponds to an integrated luminosity of 90 pb-1 collected by the Collider Detector at Fermilab. The result obtained is Dmd=0.503±0.064(stat) ±0.071(syst) ps-1.

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General Brochure, University Of North Dakota. Energy And Environmental Research Center Sep 1999

General Brochure, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Brochure including information and statistics about the Energy & Environmental Research Center (EERC).

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Capillary Surfaces In An Exotic Container: Results From Space Experiments, Paul Concus, Robert Finn, Mark M. Weislogel Sep 1999

Capillary Surfaces In An Exotic Container: Results From Space Experiments, Paul Concus, Robert Finn, Mark M. Weislogel

Mechanical and Materials Engineering Faculty Publications and Presentations

Experimental results from the Interface Configuration Experiment (ICE) performed aboard the Space Shuttle and the Mir Space Station are reported. The experiment concerns fluid interfaces in certain ‘exotic’ containers in a low-gravity environment. These containers are rotationally symmetric and have the property that for given contact angle and liquid volume, a continuum of distinct rotationally symmetric equilibrium configurations can appear, all of which have the same mechanical energy. These symmetric equilibrium configurations are unstable, in that deformations that are not rotationally symmetric can be shown mathematically to yield configurations with lower energy. It is found experimentally, in confirmation of mathematical …

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A New Family Of Relative Difference Sets In 2-Groups, James A. Davis, Jonathan Jedwab Sep 1999

A New Family Of Relative Difference Sets In 2-Groups, James A. Davis, Jonathan Jedwab

Department of Math & Statistics Faculty Publications

We recursively construct a new family of (26d+4, 8, 26d+4, 26d+1) semi-regular relative difference sets in abelian groups G relative to an elementary abelian subgroup U. The initial case d = 0 of the recursion comprises examples of (16, 8, 16, 2) relative difference sets for four distinct pairs (G, U).

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Center For Sustainable Agricultural Systems Newsletter, September/October 1999 Sep 1999

Center For Sustainable Agricultural Systems Newsletter, September/October 1999

Center for Sustainable Agricultural Systems: Newsletters (1993-2000)

Contents:

New Energy in Farming Communities

University Role in Biotechnology: How Do We Assess The Risks And Benefits?

CSAS Director Receives Honorary Degree

Sooby Now at OFRF

NCR SARE Revised Web Site

New Food Ethics Journal in 2000

DOE Announces New Wind Energy Initiative

Conference Celebrates Sustainable Ag Coming of Age in 2000

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Multiple Comparison Pruning Of Neural Networks, Donald E. Duckro Sep 1999

Multiple Comparison Pruning Of Neural Networks, Donald E. Duckro

Theses and Dissertations

Reducing a neural network's complexity improves the ability of the network to be applied to future examples. Like an overfitted regression function, neural networks may miss their target because of the excessive degrees of freedom stored up in unnecessary parameters. Over the past decade, the subject of pruning networks has produced non-statistical algorithms like Skeletonization, Optimal Brain Damage, and Optimal Brain Surgery as methods to remove connections with the least salience. There are conflicting views as to whether more than one parameter can be removed at a time. The methods proposed in this research use statistical multiple comparison procedures to …

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Anomalous Low-Temperature And High-Field Magnetoresistance In The Organic Superconductor Β″-(Bedt-Ttf)2sf5ch2cf2so3, F. Zuo, X. Su, P. Zhang, J. S. Brooks, J. Wosnitza, J. A. Schlueter, Jack M. Williams, P. G. Nixon, Rolf Walter Winter, Gary L. Gard Sep 1999

Anomalous Low-Temperature And High-Field Magnetoresistance In The Organic Superconductor Β″-(Bedt-Ttf)2sf5ch2cf2so3, F. Zuo, X. Su, P. Zhang, J. S. Brooks, J. Wosnitza, J. A. Schlueter, Jack M. Williams, P. G. Nixon, Rolf Walter Winter, Gary L. Gard

Chemistry Faculty Publications and Presentations

We report direct observations of anomalous magnetic-field and temperature dependences of the Shubnikov–de Haas oscillations in the organic superconductor β″-(BEDT-TTF)₂SF₅CH₂CF₂SO₃. Unlike other BEDT-TTF based organic superconductors, a nonmetallic temperature dependence of the background magnetoresistance is clearly observed. It is speculated that the nonmetallic behavior may arise from a partial nesting of the open orbits, similar to the field-induced density wave in the quasi-one-dimensional systems or a charge localization. The analysis of the magnetoresistance oscillations are found to deviate from the conventional Lifshitz-Kosevich description at high field and low temperatures. [S0163-1829(99)05433-8]

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